Experimental study on disintegration characteristics of carbonaceous mudstone based on energy dissipation principle

In order to explore the disintegration characteristics of carbonaceous mudstone during wet-mechanical coupling, the disintegration test of carbonaceous mudstone under vertical load and in the dry-wet cycle was carried out, and the variation of particle mass percentage with the number of dry-wet cycles in different particle size ranges was studied. Based on the principle of energy dissipation, a prediction model of energy dissipation during the disintegration of carbonaceous mudstone under different loads was established. The results show that with the increase in the number of disintegrations, the large-grained mudstone continuously disintegrates and gradually disappears, while the content of the disintegregrated material of the small-grained mudstone gradually increases and eventually gradually stabilizes. During the disintegration process, the surface energy accumulation of carbonaceous mudstone increases first and then tends to be unchanged. Under the load of 0, 50, 100 and 200 kPa, the surface energies increases obviously after the first three disintegrations, and they are 26.24, 38.05, 52.81 and 80.66 J, respectively. The energy dissipation prediction model of carbonaceous mudstone disintegration process under load is fitted, and the disintegration and fracture of carbonaceous mudstone are studied from the perspective of energy dissipation and release. The real reasons of disintegration of carbonaceous mudstone are found, which provides reference for practical engineering. © 2021, Central South University Press. All right reserved.